The terahertz (THz) gap, a frequency band lying between the microwave and infrared regions of the electromagnetic spectrum where conventional technologies are inefficient in generating and detecting the radiation, is being rapidly closed by development of new THz sources and detectors. Laser-based THz sources are of great interest due to their capability to produce coherent, single-cycle-to-multicycle, broadband (or narrowband) radiation.
Click here for original story, Understanding laser-accelerated electron radiation through terahertz emissions
Source: Phys.org